Carb vents

[Anonymous]

After much reading and questioning the local shop, I am still confused about the vent lines for the carbs. My GS is a 1978 1000 with Mikuni carbs. There are ports on carbs 2,3 and 4 and I need to know where the vacuum line for the fuel petcock is attached, and which of the ports are for vent only.

I really enjoy my bike and would appreciate any help with this.

Thanks!!

[cloudbreakmd]

If you are looking downward at the carbs, there should only be one nipple sticking up from the carb boots on the engine side. That is what hooks up to your petcock.

[ptm]

On my '78 750, with #1 at the left as you sit on the bike

#1 carb has no vent nipple
#2 carb is vented to atmosphere - the hose runs up and over the air box
#3 carb vent hose goes to the petcock
#4 carb is vented to atmosphere - the hose runs up and over the air box

[KEITH KRAUSE]

Re: Carb vents

After much reading and questioning the local shop, I am still confused about the vent lines for the carbs. My GS is a 1978 1000 with Mikuni carbs. There are ports on carbs 2,3 and 4 and I need to know where the vacuum line for the fuel petcock is attached, and which of the ports are for vent only.

I really enjoy my bike and would appreciate any help with this.

Thanks!!

#3 nipple supplies vacuum to the petcock.
Be sure the #2 and 4 float bowl venting nipples/hoses are clear and routed under the seat.
If you run pod filters, remove the vent lines and leave the nipples open. This will eliminate fuel starvation with pod filters.